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Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures. Liquid helium may show superfluidity . At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (−452.20 °F; 4.15 K).
A melting-point apparatus is a scientific instrument used to determine the melting point of a substance. Some types of melting-point apparatuses include the Thiele tube , Fisher-Johns apparatus, Gallenkamp (Electronic) melting-point apparatus and automatic melting-point apparatus.
The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point or boiling point of a substance. The apparatus resembles a glass test tube with an attached handle.
2 He helium; use: 0.0829 CRC: 0.08 LNG: 0.0829 WEL: 0.083 ... Values refer to the enthalpy change in the conversion of liquid to gas at the boiling point (normal, 101 ...
2 He helium; use: 4.222 K: −268.928 °C: ... "Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in ... Melting points of the elements ...
Boca Raton, Florida, 2003; Section 6, Fluid Properties; Critical Constants. Also agrees with Celsius values from Section 4: Properties of the Elements and Inorganic Compounds, Melting, Boiling, Triple, and Critical Point Temperatures of the Elements Estimated accuracy for Tc and Pc is indicated by the number of digits.
The apparatus is heated. Dissolved gases evolve from the sample first, and the air in the capillary tube expands. Once the sample starts to boil, heating is stopped, and the temperature starts to fall. The temperature at which the liquid sample is sucked into the sealed capillary is the boiling point of the sample. [1] [2] [3] [4]
Ebullioscope a device for measuring the boiling point of a liquid. This device is also part of a method that uses the effect of boiling point elevation for calculating the molecular mass of a solvent. See also Thermal analysis, Heat.